A centrifugal compressor employs a wheel or impeller mounted on a rotatable shaft positioned within a stationary housing. The wheel defines a gas flow path from the entrance to the exit. Low solidity airfoil diffusers have been used successfully as efficient and compact dynamic pressure recovery devices in industrial centrifugal compressor stages. Typically such diffusers have a cascade of two-dimensional airfoil blades or vanes distributed circumferentially at close proximity to the impeller exit. The fundamental characteristic of this type of diffuser is the lack of a geometrical throat that permits it to increase the operating range without the risk of flow choking. This type of diffuser geometry has a large flow range close to that of vaneless diffusers while achieving pressure recovery levels close to that of channel type diffusers. Recently however, due to increased competitiveness in the process industry, centrifugal compressor operating ranges are being challenged to increase beyond the existing ranges of the present two-dimensional diffuser configurations.